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|
// The High Performance Login Daemon (works with tunnel mode)
// $Id: logind.c,v 1.1 2009/06/09 13:13:42 piaip Exp piaip $
//
// Create: Hung-Te Lin <piaip@csie.ntu.edu.tw>
// Contributors: wens, kcwu
// Initial Date: 2009/06/01
//
// Copyright (C) 2009, Hung-Te Lin <piaip@csie.ntu.edu.tw>
// All rights reserved
// TODO:
// 1. cache guest's usernum and check if too many guests online
// 2. [drop] change close connection to 'wait until user hit then close'
// 3. make original port information in margs(mbbsd)?
// 4. may rebind ports if get HUP (maybe impossible due to setuid).
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <signal.h>
#include <event.h>
#define _BBS_UTIL_C_
#include "bbs.h"
#include "banip.h"
#include "logind.h"
#ifndef OPTIMIZE_SOCKET
#define OPTIMIZE_SOCKET(sock) do {} while(0)
#endif
#ifndef SOCKET_QLEN
#define SOCKET_QLEN (10)
#endif
#ifndef AUTHFAIL_SLEEP_SEC
#define AUTHFAIL_SLEEP_SEC (15)
#endif
#ifndef OVERLOAD_SLEEP_SEC
#define OVERLOAD_SLEEP_SEC (60)
#endif
#ifndef BAN_SLEEP_SEC
#define BAN_SLEEP_SEC (60)
#endif
#define MAX_TEXT_SCREEN_LINES (24)
///////////////////////////////////////////////////////////////////////
// global variables
int g_tunnel; // tunnel for service daemon
int g_reload_data = 1; // request to reload data
// server status
int g_overload = 0;
int g_banned = 0;
int g_verbose = 0;
///////////////////////////////////////////////////////////////////////
// login context, constants and states
enum {
LOGIN_STATE_START = 1,
LOGIN_STATE_USERID,
LOGIN_STATE_PASSWD,
LOGIN_STATE_AUTH,
LOGIN_HANDLE_WAIT = 1,
LOGIN_HANDLE_BEEP,
LOGIN_HANDLE_OUTC,
LOGIN_HANDLE_REDRAW_USERID,
LOGIN_HANDLE_BS,
LOGIN_HANDLE_PROMPT_PASSWD,
LOGIN_HANDLE_START_AUTH,
AUTH_RESULT_STOP = -2,
AUTH_RESULT_FREEID = -1,
AUTH_RESULT_FAIL = 0,
AUTH_RESULT_RETRY = AUTH_RESULT_FAIL,
AUTH_RESULT_OK = 1,
};
#ifdef CONVERT
#define IDBOXLEN (IDLEN+2) // one extra char for encoding
#else
#define IDBOXLEN (IDLEN+1)
#endif
typedef struct {
int state;
int retry;
int encoding;
int t_lines;
int t_cols;
int icurr; // cursor (only available in userid input mode)
Fnv32_t client_code;
char userid [IDBOXLEN];
char pad0; // for safety
char passwd [PASSLEN+1];
char pad1; // for safety
char hostip [IPV4LEN+1];
char pad2; // for safety
char port [IDLEN+1];
char pad3; // for safety
} login_ctx;
typedef struct {
struct bufferevent *bufev;
struct event ev;
TelnetCtx telnet;
login_ctx ctx;
} login_conn_ctx;
typedef struct {
struct event ev;
int port;
} bind_event;
void
login_ctx_init(login_ctx *ctx)
{
assert(ctx);
memset(ctx, 0, sizeof(login_ctx));
ctx->client_code = FNV1_32_INIT;
ctx->state = LOGIN_STATE_START;
}
int
login_ctx_retry(login_ctx *ctx)
{
assert(ctx);
ctx->state = LOGIN_STATE_START;
ctx->encoding = 0;
memset(ctx->userid, 0, sizeof(ctx->userid));
memset(ctx->passwd, 0, sizeof(ctx->passwd));
ctx->icurr = 0;
// do not touch hostip, client code, t_*
ctx->retry ++;
return ctx->retry;
}
int
login_ctx_handle(login_ctx *ctx, int c)
{
int l;
assert(ctx);
switch(ctx->state)
{
case LOGIN_STATE_START:
case LOGIN_STATE_USERID:
l = strlen(ctx->userid);
switch(c)
{
case KEY_ENTER:
ctx->state = LOGIN_STATE_PASSWD;
return LOGIN_HANDLE_PROMPT_PASSWD;
case KEY_BS:
if (!l || !ctx->icurr)
return LOGIN_HANDLE_BEEP;
if (ctx->userid[ctx->icurr])
{
ctx->icurr--;
memmove(ctx->userid + ctx->icurr,
ctx->userid + ctx->icurr+1,
l - ctx->icurr);
return LOGIN_HANDLE_REDRAW_USERID;
}
// simple BS
ctx->icurr--;
ctx->userid[l-1] = 0;
return LOGIN_HANDLE_BS;
case Ctrl('D'):
case KEY_DEL:
if (!l || !ctx->userid[ctx->icurr])
return LOGIN_HANDLE_BEEP;
memmove(ctx->userid + ctx->icurr,
ctx->userid + ctx->icurr+1,
l - ctx->icurr);
return LOGIN_HANDLE_REDRAW_USERID;
case Ctrl('B'):
case KEY_LEFT:
if (ctx->icurr)
ctx->icurr--;
return LOGIN_HANDLE_REDRAW_USERID;
case Ctrl('F'):
case KEY_RIGHT:
if (ctx->userid[ctx->icurr])
ctx->icurr ++;
return LOGIN_HANDLE_REDRAW_USERID;
case KEY_HOME:
ctx->icurr = 0;
return LOGIN_HANDLE_REDRAW_USERID;
case KEY_END:
ctx->icurr = l;
return LOGIN_HANDLE_REDRAW_USERID;
case Ctrl('K'):
if (!l || !ctx->userid[ctx->icurr])
return LOGIN_HANDLE_BEEP;
memset( ctx->userid + ctx->icurr, 0,
l - ctx->icurr +1);
return LOGIN_HANDLE_REDRAW_USERID;
}
// default: insert characters
if (!isascii(c) || !isprint(c) ||
c == ' ' ||
l+1 >= sizeof(ctx->userid))
return LOGIN_HANDLE_BEEP;
memmove(ctx->userid + ctx->icurr + 1,
ctx->userid + ctx->icurr,
l - ctx->icurr +1);
ctx->userid[ctx->icurr++] = c;
if (ctx->icurr != l+1)
return LOGIN_HANDLE_REDRAW_USERID;
return LOGIN_HANDLE_OUTC;
case LOGIN_STATE_PASSWD:
l = strlen(ctx->passwd);
if (c == KEY_ENTER)
{
// no matter what, apply the passwd
ctx->state = LOGIN_STATE_AUTH;
return LOGIN_HANDLE_START_AUTH;
}
if (c == KEY_BS)
{
if (!l)
return LOGIN_HANDLE_BEEP;
ctx->passwd[l-1] = 0;
return LOGIN_HANDLE_WAIT;
}
// XXX for backward compatibility,
// we'd support non-ASCII characters in PW.
if ( (isascii(c) && !isprint(c)) ||
l+1 >= sizeof(ctx->passwd))
return LOGIN_HANDLE_BEEP;
ctx->passwd[l] = c;
return LOGIN_HANDLE_WAIT;
default:
break;
}
return LOGIN_HANDLE_BEEP;
}
///////////////////////////////////////////////////////////////////////
// I/O
static ssize_t
_buff_write(login_conn_ctx *conn, const void *buf, size_t nbytes)
{
return bufferevent_write(conn->bufev, buf, nbytes);
}
///////////////////////////////////////////////////////////////////////
// Mini Terminal
static void
_mt_bell(login_conn_ctx *conn)
{
static const char b = Ctrl('G');
_buff_write(conn, &b, 1);
}
static void
_mt_bs(login_conn_ctx *conn)
{
static const char cmd[] = "\b \b";
_buff_write(conn, cmd, sizeof(cmd)-1);
}
static void
_mt_home(login_conn_ctx *conn)
{
static const char cmd[] = ESC_STR "[H";
_buff_write(conn, cmd, sizeof(cmd)-1);
}
static void
_mt_clrtoeol(login_conn_ctx *conn)
{
static const char cmd[] = ESC_STR "[K";
_buff_write(conn, cmd, sizeof(cmd)-1);
}
static void
_mt_clear(login_conn_ctx *conn)
{
static const char cmd[] = ESC_STR "[2J";
_mt_home(conn);
_buff_write(conn, cmd, sizeof(cmd)-1);
}
static void
_mt_move_yx(login_conn_ctx *conn, const char *mcmd)
{
static const char cmd1[] = ESC_STR "[",
cmd2[] = "H";
_buff_write(conn, cmd1, sizeof(cmd1)-1);
_buff_write(conn, mcmd, strlen(mcmd));
_buff_write(conn, cmd2, sizeof(cmd2)-1);
}
///////////////////////////////////////////////////////////////////////
// ANSI/vt100/vt220 special keys
static int
_handle_term_keys(char **pstr, int *plen)
{
char *str = *pstr;
assert(plen && pstr && *pstr && *plen > 0);
// fprintf(stderr, "handle_term: input = %d\r\n", *plen);
// 1. check ESC
(*plen)--; (*pstr)++;
if (*str != ESC_CHR)
{
int c = (unsigned char)*str;
switch(c)
{
case KEY_CR:
return KEY_ENTER;
case KEY_LF:
return 0; // to ignore
case Ctrl('A'):
return KEY_HOME;
case Ctrl('E'):
return KEY_END;
// case '\b':
case Ctrl('H'):
case 127:
return KEY_BS;
}
return c;
}
// 2. check O / [
if (!*plen)
return KEY_ESC;
(*plen)--; (*pstr)++; str++;
if (*str != 'O' && *str != '[')
return *str;
// 3. alpha: end, digit: one more (~)
if (!*plen)
return *str;
(*plen)--; (*pstr)++; str++;
if (!isascii(*str))
return KEY_UNKNOWN;
if (isdigit(*str))
{
if (*plen)
{
(*plen)--; (*pstr)++;
}
switch(*str)
{
case '1':
// fprintf(stderr, "got KEY_HOME.\r\n");
return KEY_HOME;
case '4':
// fprintf(stderr, "got KEY_END.\r\n");
return KEY_END;
case '3':
// fprintf(stderr, "got KEY_DEL.\r\n");
return KEY_DEL;
default:
// fprintf(stderr, "got KEY_UNKNOWN.\r\n");
return KEY_UNKNOWN;
}
}
if (isalpha(*str))
{
switch(*str)
{
case 'C':
// fprintf(stderr, "got KEY_RIGHT.\r\n");
return KEY_RIGHT;
case 'D':
// fprintf(stderr, "got KEY_LEFT.\r\n");
return KEY_LEFT;
default:
return KEY_UNKNOWN;
}
}
// unknown
return KEY_UNKNOWN;
}
///////////////////////////////////////////////////////////////////////
// Telnet Protocol
static void
_telnet_resize_term_cb(void *resize_arg, int w, int h)
{
login_ctx *ctx = (login_ctx*) resize_arg;
assert(ctx);
ctx->t_lines = h;
ctx->t_cols = w;
}
static void
_telnet_update_cc_cb(void *cc_arg, unsigned char c)
{
login_ctx *ctx = (login_ctx*) cc_arg;
assert(ctx);
// fprintf(stderr, "update cc: %08lX", (unsigned long)ctx->client_code);
FNV1A_CHAR(c, ctx->client_code);
// fprintf(stderr, "-> %08lX\r\n", (unsigned long)ctx->client_code);
}
static void
_telnet_write_data_cb(void *write_arg, int fd, const void *buf, size_t nbytes)
{
login_conn_ctx *conn = (login_conn_ctx *)write_arg;
_buff_write(conn, buf, nbytes);
}
const static struct TelnetCallback
telnet_callback = {
_telnet_write_data_cb,
_telnet_resize_term_cb,
#ifdef DETECT_CLIENT
_telnet_update_cc_cb,
#else
NULL,
#endif
};
///////////////////////////////////////////////////////////////////////
// Socket Option
static int
_set_connection_opt(int sock)
{
const int szrecv = 1024, szsend=4096;
const struct linger lin = {0};
// keep alive: server will check target connection. (around 2hr)
const int on = 1;
setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void*)&on, sizeof(on));
// fast close
setsockopt(sock, SOL_SOCKET, SO_LINGER, &lin, sizeof(lin));
// adjust transmission window
setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void*)&szrecv, sizeof(szrecv));
setsockopt(sock, SOL_SOCKET, SO_SNDBUF, (void*)&szsend, sizeof(szsend));
OPTIMIZE_SOCKET(sock);
return 0;
}
static int
_set_bind_opt(int sock)
{
const int on = 1;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*)&on, sizeof(on));
_set_connection_opt(sock);
return 0;
}
///////////////////////////////////////////////////////////////////////
// Draw Screen
#ifdef STR_GUEST
# define MSG_GUEST ",或以[" STR_GUEST "]參觀"
#else
# define MSG_GUEST ""
#endif
#ifdef STR_REGNEW
# define MSG_REGNEW ",或以[new]註冊"
#else
# define MSG_REGNEW
#endif
#define BOTTOM_YX "24;1"
#define LOGIN_PROMPT_MSG ANSI_RESET "請輸入代號" MSG_GUEST MSG_REGNEW ": " ANSI_REVERSE
#define LOGIN_PROMPT_YX "21;1"
#define LOGIN_PROMPT_END ANSI_RESET
#define PASSWD_PROMPT_MSG ANSI_RESET MSG_PASSWD
#define PASSWD_PROMPT_YX "22;1"
#define PASSWD_CHECK_MSG ANSI_RESET "正在檢查帳號與密碼..."
#define PASSWD_CHECK_YX PASSWD_PROMPT_YX
#define AUTH_SUCCESS_MSG ANSI_RESET "密碼正確! 開始登入系統...\r\n"
#define AUTH_SUCCESS_YX PASSWD_PROMPT_YX
#define FREEAUTH_SUCCESS_MSG ANSI_RESET "開始登入系統...\r\n"
#define FREEAUTH_SUCCESS_YX AUTH_SUCCESS_YX
#define AUTH_FAIL_MSG ANSI_RESET ERR_PASSWD
#define AUTH_FAIL_YX PASSWD_PROMPT_YX
#define USERID_EMPTY_MSG ANSI_RESET "請重新輸入。"
#define USERID_EMPTY_YX PASSWD_PROMPT_YX
#define SERVICE_FAIL_MSG ANSI_COLOR(0;1;31) "抱歉,系統目前無法使用,請稍候再試。" ANSI_RESET "\r\n"
#define SERVICE_FAIL_YX BOTTOM_YX
#define OVERLOAD_CPU_MSG "系統過載, 請稍後再來...\r\n"
#define OVERLOAD_CPU_YX BOTTOM_YX
#define OVERLOAD_USER_MSG "由於人數過多,請您稍後再來...\r\n"
#define OVERLOAD_USER_YX BOTTOM_YX
#define FN_WELCOME BBSHOME "/etc/Welcome"
#define FN_GOODBYE BBSHOME "/etc/goodbye"
#define FN_BAN BBSHOME "/" BAN_FILE
static char *welcome_screen, *goodbye_screen, *ban_screen;
static void
load_text_screen_file(const char *filename, char **pptr)
{
FILE *fp;
off_t sz, wsz, psz;
char *p, *s = NULL;
int max_lines = MAX_TEXT_SCREEN_LINES;
sz = dashs(filename);
if (sz < 1)
{
free(*pptr);
*pptr = NULL;
return;
}
wsz = sz*2 +1; // *2 for cr+lf, extra one byte for safe strchr().
// XXX TODO use realloc?
assert(pptr);
s = *pptr;
s = realloc(s, wsz);
*pptr = s;
if (!s)
return;
memset(s, 0, wsz);
p = s;
psz = wsz;
fp = fopen(filename, "rt");
if (!fp)
{
free(s);
return;
}
while ( max_lines-- > 0 &&
fgets(p, psz, fp))
{
psz -= strlen(p);
p += strlen(p);
*p ++ = '\r';
}
fclose(fp);
*pptr = s;
}
static void regular_check();
static void
reload_data()
{
regular_check();
if (!g_reload_data)
return;
fprintf(stderr, "start reloading data.\r\n");
g_reload_data = 0;
load_text_screen_file(FN_WELCOME, &welcome_screen);
load_text_screen_file(FN_GOODBYE, &goodbye_screen);
load_text_screen_file(FN_BAN, &ban_screen);
}
static void
draw_text_screen(login_conn_ctx *conn, const char *scr)
{
const char *ps, *pe;
char buf[64];
time4_t now;
_mt_clear(conn);
if (!scr || !*scr)
return;
// draw the screen from text file
// XXX Because the text file may contain a very small subset of escape sequence
// *t[Cdate] and *u[SHM->UTMPnumber], we implement a tiny version of
// expand_esc_star here.
ps = pe = scr;
while(pe && *pe)
{
// find a safe range between (ps, pe) to print
pe = strchr(pe, ESC_CHR);
if (!pe)
{
// no more escapes, print all.
_buff_write(conn, ps, strlen(ps));
break;
}
// let's look ahead
pe++;
// if not esc_star, search for next.
if (*pe != '*')
continue;
// flush previous data
_buff_write(conn, ps, pe - ps - 1);
buf[0] = 0; pe++;
// expand the star
switch(*pe)
{
case 't': // current time
// strcpy(buf, "[date]");
now = time(0);
strlcpy(buf, Cdate(&now), sizeof(buf));
break;
case 'u': // current online users
// strcpy(buf, "[SHM->UTMPnumber]");
snprintf(buf, sizeof(buf), "%d", SHM->UTMPnumber);
break;
}
if(buf[0])
_buff_write(conn, buf, strlen(buf));
pe ++;
ps = pe;
}
}
static void
draw_goodbye(login_conn_ctx *conn)
{
draw_text_screen(conn, goodbye_screen);
}
static void
draw_userid_prompt(login_conn_ctx *conn, const char *uid, int icurr)
{
char box[IDBOXLEN];
_mt_move_yx(conn, LOGIN_PROMPT_YX); _mt_clrtoeol(conn);
_buff_write(conn, LOGIN_PROMPT_MSG, sizeof(LOGIN_PROMPT_MSG)-1);
// draw input box
memset(box, ' ', sizeof(box));
if (uid) memcpy(box, uid, strlen(uid));
_buff_write (conn, box, sizeof(box));
memset(box, '\b',sizeof(box));
_buff_write (conn, box, sizeof(box)-icurr);
}
static void
draw_userid_prompt_end(login_conn_ctx *conn)
{
if (g_verbose) fprintf(stderr, "reset connection attribute.\r\n");
_buff_write(conn, LOGIN_PROMPT_END, sizeof(LOGIN_PROMPT_END)-1);
}
static void
draw_passwd_prompt(login_conn_ctx *conn)
{
_mt_move_yx(conn, PASSWD_PROMPT_YX); _mt_clrtoeol(conn);
_buff_write(conn, PASSWD_PROMPT_MSG, sizeof(PASSWD_PROMPT_MSG)-1);
}
static void
draw_empty_userid_warn(login_conn_ctx *conn)
{
_mt_move_yx(conn, USERID_EMPTY_YX); _mt_clrtoeol(conn);
_buff_write(conn, USERID_EMPTY_MSG, sizeof(USERID_EMPTY_MSG)-1);
}
static void
draw_check_passwd(login_conn_ctx *conn)
{
_mt_move_yx(conn, PASSWD_CHECK_YX); _mt_clrtoeol(conn);
_buff_write(conn, PASSWD_CHECK_MSG, sizeof(PASSWD_CHECK_MSG)-1);
}
static void
draw_auth_success(login_conn_ctx *conn, int free)
{
if (free)
{
_mt_move_yx(conn, FREEAUTH_SUCCESS_YX); _mt_clrtoeol(conn);
_buff_write(conn, FREEAUTH_SUCCESS_MSG, sizeof(FREEAUTH_SUCCESS_MSG)-1);
} else {
_mt_move_yx(conn, AUTH_SUCCESS_YX); _mt_clrtoeol(conn);
_buff_write(conn, AUTH_SUCCESS_MSG, sizeof(AUTH_SUCCESS_MSG)-1);
}
}
static void
draw_auth_fail(login_conn_ctx *conn)
{
_mt_move_yx(conn, AUTH_FAIL_YX); _mt_clrtoeol(conn);
_buff_write(conn, AUTH_FAIL_MSG, sizeof(AUTH_FAIL_MSG)-1);
}
static void
draw_service_failure(login_conn_ctx *conn)
{
_mt_move_yx(conn, SERVICE_FAIL_YX); _mt_clrtoeol(conn);
_buff_write(conn, SERVICE_FAIL_MSG, sizeof(SERVICE_FAIL_MSG)-1);
}
static void
draw_overload(login_conn_ctx *conn, int type)
{
if (type == 1)
{
_mt_move_yx(conn, OVERLOAD_CPU_MSG); _mt_clrtoeol(conn);
_buff_write(conn, OVERLOAD_CPU_MSG, sizeof(OVERLOAD_CPU_MSG)-1);
}
else if (type == 2)
{
_mt_move_yx(conn, OVERLOAD_USER_MSG); _mt_clrtoeol(conn);
_buff_write(conn, OVERLOAD_USER_MSG, sizeof(OVERLOAD_USER_MSG)-1);
}
else {
assert(false);
_mt_move_yx(conn, OVERLOAD_CPU_MSG); _mt_clrtoeol(conn);
_buff_write(conn, OVERLOAD_CPU_MSG, sizeof(OVERLOAD_CPU_MSG)-1);
}
}
///////////////////////////////////////////////////////////////////////
// BBS Logic
#define REGULAR_CHECK_DURATION (5)
static void
regular_check()
{
// cache results
static time_t last_check_time = 0;
time_t now = time(0);
if ( now - last_check_time < REGULAR_CHECK_DURATION)
return;
last_check_time = now;
g_overload = 0;
g_banned = 0;
if (cpuload(NULL) > MAX_CPULOAD)
{
g_overload = 1;
}
else if (SHM->UTMPnumber >= MAX_ACTIVE
#ifdef DYMAX_ACTIVE
|| (SHM->GV2.e.dymaxactive > 2000 &&
SHM->UTMPnumber >= SHM->GV2.e.dymaxactive)
#endif
)
{
++SHM->GV2.e.toomanyusers;
g_overload = 2;
}
if (dashf(FN_BAN))
{
g_banned = 1;
load_text_screen_file(FN_BAN, &ban_screen);
}
}
static int
check_banip(char *host)
{
uint32_t thisip = ipstr2int(host);
return uintbsearch(thisip, &banip[1], banip[0]) ? 1 : 0;
}
static const char *
auth_is_free_userid(const char *userid)
{
#if defined(STR_GUEST) && !defined(NO_GUEST_ACCOUNT_REG)
if (strcasecmp(userid, STR_GUEST) == 0)
return STR_GUEST;
#endif
#ifdef STR_REGNEW
if (strcasecmp(userid, STR_REGNEW) == 0)
return STR_REGNEW;
#endif
return NULL;
}
// NOTE ctx->passwd will be destroyed (must > PASSLEN+1)
// NOTE ctx->userid may be changed (must > IDLEN+1)
static int
auth_user_challenge(login_ctx *ctx)
{
char *uid = ctx->userid,
*passbuf = ctx->passwd;
const char *free_uid = auth_is_free_userid(uid);
if (free_uid)
{
strlcpy(ctx->userid, free_uid, sizeof(ctx->userid));
return AUTH_RESULT_FREEID;
}
// reuse cuser
memset(&cuser, 0, sizeof(cuser));
if( initcuser(uid) < 1 || !cuser.userid[0] ||
!checkpasswd(cuser.passwd, passbuf) )
{
if (cuser.userid[0])
strcpy(uid, cuser.userid);
return AUTH_RESULT_FAIL;
}
// normalize user id
strcpy(uid, cuser.userid);
return AUTH_RESULT_OK;
}
static int
start_service(int fd, login_ctx *ctx)
{
login_data ld = {0};
int ack = 0;
if (!g_tunnel)
return 0;
ld.cb = sizeof(ld);
strlcpy(ld.userid, ctx->userid, sizeof(ld.userid));
strlcpy(ld.hostip, ctx->hostip, sizeof(ld.hostip));
strlcpy(ld.port, ctx->port, sizeof(ld.port));
ld.encoding = ctx->encoding;
ld.client_code = ctx->client_code;
ld.t_lines = 24; // default size
ld.t_cols = 80;
if (ctx->t_lines > ld.t_lines)
ld.t_lines = ctx->t_lines;
if (ctx->t_cols > ld.t_cols)
ld.t_cols = ctx->t_cols;
if (g_verbose) fprintf(stderr, "start new service: %s@%s:%s #%d\r\n",
ld.userid, ld.hostip, ld.port, fd);
// deliver the fd to hosting service
if (send_remote_fd(g_tunnel, fd) < 0)
return ack;
// deliver the login data to hosting servier
if (towrite(g_tunnel, &ld, sizeof(ld)) <= 0)
return ack;
// wait service to response
read(g_tunnel, &ack, sizeof(ack));
return ack;
}
static int
auth_start(int fd, login_conn_ctx *conn)
{
login_ctx *ctx = &conn->ctx;
int isfree = 1, was_valid_uid = 0;
draw_check_passwd(conn);
if (is_validuserid(ctx->userid))
{
// ctx content may be changed.
was_valid_uid = 1;
switch (auth_user_challenge(ctx))
{
case AUTH_RESULT_FAIL:
logattempt(ctx->userid , '-', time(0), ctx->hostip);
break;
case AUTH_RESULT_OK:
isfree = 0;
logattempt(ctx->userid , ' ', time(0), ctx->hostip);
// share FREEID case, no break here!
case AUTH_RESULT_FREEID:
draw_auth_success(conn, isfree);
if (!start_service(fd, ctx))
{
// too bad, we can't start service.
draw_service_failure(conn);
return AUTH_RESULT_STOP;
}
return AUTH_RESULT_OK;
default:
assert(false);
break;
}
}
// auth fail.
_mt_bell(conn);
// if fail, restart
if (login_ctx_retry(ctx) >= LOGINATTEMPTS)
{
// end retry.
draw_goodbye(conn);
if (g_verbose) fprintf(stderr, "auth fail (goodbye): %s@%s #%d...",
conn->ctx.userid, conn->ctx.hostip, fd);
return AUTH_RESULT_STOP;
}
// prompt for retry
if (was_valid_uid)
draw_auth_fail(conn);
else
draw_empty_userid_warn(conn);
ctx->state = LOGIN_STATE_USERID;
draw_userid_prompt(conn, NULL, 0);
return AUTH_RESULT_RETRY;
}
///////////////////////////////////////////////////////////////////////
// Event callbacks
static struct event ev_sighup, ev_tunnel;
static void
sighup_cb(int signal, short event, void *arg)
{
fprintf(stderr, "caught sighup (request to reload)\r\n");
g_reload_data = 1;
}
static void
endconn_cb(int fd, short event, void *arg)
{
login_conn_ctx *conn = (login_conn_ctx*) arg;
if (g_verbose) fprintf(stderr,
"login_conn_remove: removed connection (%s@%s) #%d...",
conn->ctx.userid, conn->ctx.hostip, fd);
event_del(&conn->ev);
bufferevent_free(conn->bufev);
close(fd);
free(conn);
if (g_verbose) fprintf(stderr, " done.\r\n");
}
static void
login_conn_remove(login_conn_ctx *conn, int fd, int sleep_sec)
{
if (!sleep_sec)
{
endconn_cb(fd, EV_TIMEOUT, (void*) conn);
} else {
struct timeval tv = { sleep_sec, 0};
event_del(&conn->ev);
event_set(&conn->ev, fd, EV_PERSIST, endconn_cb, conn);
event_add(&conn->ev, &tv);
if (g_verbose) fprintf(stderr,
"login_conn_remove: stop conn #%d in %d seconds later.\r\n",
fd, sleep_sec);
}
}
static void
client_cb(int fd, short event, void *arg)
{
login_conn_ctx *conn = (login_conn_ctx*) arg;
int len, r;
unsigned char buf[64], ch, *s = buf;
// ignore clients that timeout
if (event & EV_TIMEOUT)
return;
// XXX will this happen?
if (!(event & EV_READ))
return;
if ( (len = read(fd, buf, sizeof(buf))) <= 0)
{
if (errno == EINTR || errno == EAGAIN)
return;
// close connection
login_conn_remove(conn, fd, 0);
return;
}
len = telnet_process(&conn->telnet, buf, len);
while (len > 0)
{
int c = _handle_term_keys((char**)&s, &len);
// for zero, ignore.
if (!c)
continue;
if (c == KEY_UNKNOWN)
{
_mt_bell(conn);
continue;
}
// deal with context
switch ( login_ctx_handle(&conn->ctx, c) )
{
case LOGIN_HANDLE_WAIT:
break;
case LOGIN_HANDLE_BEEP:
_mt_bell(conn);
break;
case LOGIN_HANDLE_BS:
_mt_bs(conn);
break;
case LOGIN_HANDLE_REDRAW_USERID:
if (g_verbose) fprintf(stderr,
"redraw userid: id=[%s], icurr=%d\r\n",
conn->ctx.userid, conn->ctx.icurr);
draw_userid_prompt(conn, conn->ctx.userid, conn->ctx.icurr);
break;
case LOGIN_HANDLE_OUTC:
ch = c;
_buff_write(conn, &ch, 1);
break;
case LOGIN_HANDLE_PROMPT_PASSWD:
// because prompt would reverse attribute, reset here.
draw_userid_prompt_end(conn);
#ifdef DETECT_CLIENT
// stop detection
conn->telnet.cc_arg = NULL;
#endif
if (conn->ctx.userid[0])
{
char *uid = conn->ctx.userid;
char *uid_lastc = uid + strlen(uid)-1;
draw_passwd_prompt(conn);
#ifdef CONVERT
// convert encoding if required
switch(*uid_lastc)
{
case '.': // GB mode
conn->ctx.encoding = CONV_GB;
*uid_lastc = 0;
break;
case ',': // UTF-8 mode
conn->ctx.encoding = CONV_UTF8;
*uid_lastc = 0;
break;
}
#endif
// accounts except free_auth [guest / new]
// require passwd.
if (!auth_is_free_userid(uid))
break;
}
// force changing state
conn->ctx.state = LOGIN_STATE_AUTH;
// XXX share start auth, no break here.
case LOGIN_HANDLE_START_AUTH:
if ((r = auth_start(fd, conn)) != AUTH_RESULT_RETRY)
{
login_conn_remove(conn, fd,
(r == AUTH_RESULT_OK) ? 0 : AUTHFAIL_SLEEP_SEC);
return;
}
break;
}
}
}
static void
listen_cb(int fd, short event, void *arg)
{
int cfd;
struct sockaddr_in xsin = {0};
socklen_t szxsin = sizeof(xsin);
login_conn_ctx *conn;
bind_event *pbindev = (bind_event*) arg;
if ((cfd = accept(fd, (struct sockaddr *)&xsin, &szxsin)) < 0 )
return;
if ((conn = malloc(sizeof(login_conn_ctx))) == NULL) {
close(cfd);
return;
}
memset(conn, 0, sizeof(login_conn_ctx));
if ((conn->bufev = bufferevent_new(cfd, NULL, NULL, NULL, NULL)) == NULL) {
free(conn);
close(cfd);
return;
}
reload_data();
login_ctx_init(&conn->ctx);
// initialize telnet protocol
telnet_ctx_init(&conn->telnet, &telnet_callback, cfd);
telnet_ctx_set_write_arg (&conn->telnet, (void*) conn); // use conn for buffered events
telnet_ctx_set_resize_arg(&conn->telnet, (void*) &conn->ctx);
#ifdef DETECT_CLIENT
telnet_ctx_set_cc_arg(&conn->telnet, (void*) &conn->ctx);
#endif
// better send after all parameters were set
telnet_ctx_send_init_cmds(&conn->telnet);
// get remote ip & local port info
inet_ntop(AF_INET, &xsin.sin_addr, conn->ctx.hostip, sizeof(conn->ctx.hostip));
snprintf(conn->ctx.port, sizeof(conn->ctx.port), "%u", pbindev->port); // ntohs(xsin.sin_port));
if (g_verbose) fprintf(stderr,
"new connection: %s:%s\r\n", conn->ctx.hostip, conn->ctx.port);
// set events
event_set(&conn->ev, cfd, EV_READ|EV_PERSIST, client_cb, conn);
event_add(&conn->ev, NULL);
// check ban here? XXX can we directly use xsin.sin_addr instead of ASCII form?
if (g_banned || check_banip(conn->ctx.hostip) )
{
// draw ban screen, if available. (for banip, this is empty).
draw_text_screen(conn, ban_screen);
login_conn_remove(conn, fd, BAN_SLEEP_SEC);
return;
}
// draw banner
#ifdef INSCREEN
_buff_write(conn, INSCREEN, sizeof(INSCREEN));
#endif
// XXX check system load here.
if (g_overload)
{
draw_overload(conn, g_overload);
login_conn_remove(conn, fd, OVERLOAD_SLEEP_SEC);
return;
} else {
draw_text_screen(conn, welcome_screen);
draw_userid_prompt(conn, NULL, 0);
}
}
static void
tunnel_cb(int fd, short event, void *arg)
{
int cfd;
if ((cfd = accept(fd, NULL, NULL)) < 0 )
return;
_set_connection_opt(cfd);
// got new tunnel
if (g_tunnel)
close(g_tunnel);
g_tunnel = cfd;
}
///////////////////////////////////////////////////////////////////////
// Main
#ifndef LOGIND_TUNNEL_PATH
#define LOGIND_TUNNEL_PATH BBSHOME "/run/logind.tunnel"
#endif
#ifndef FN_BINDLIST
#define FN_BINDLIST BBSHOME "/etc/logind_ports" // a file with list of ports to bind.
#endif
static int
bind_port(int port)
{
char buf[STRLEN];
int sfd;
bind_event *pev = NULL;
snprintf(buf, sizeof(buf), "*:%d", port);
fprintf(stderr,"binding to port: %d...", port);
if ( (sfd = tobindex(buf, SOCKET_QLEN, _set_bind_opt, 1)) < 0 )
{
fprintf(stderr, "cannot bind to port: %d. abort.\r\n", port);
return -1;
}
pev = malloc (sizeof(bind_event));
memset(pev, 0, sizeof(bind_event));
assert(pev);
pev->port = port;
event_set(&pev->ev, sfd, EV_READ | EV_PERSIST, listen_cb, pev);
event_add(&pev->ev, NULL);
fprintf(stderr,"ok. \r\n");
return 0;
}
int
main(int argc, char *argv[])
{
int ch, port = 0, bound_ports = 0, tfd, as_daemon = 1;
FILE *fp;
const char *tunnel_path = LOGIND_TUNNEL_PATH;
const char *config_file = FN_BINDLIST;
Signal(SIGPIPE, SIG_IGN);
while ( (ch = getopt(argc, argv, "f:p:t:hDv")) != -1 )
{
switch( ch ){
case 'f':
config_file = optarg;
break;
case 'p':
if (optarg) port = atoi(optarg);
break;
case 't':
tunnel_path = optarg;
break;
case 'D':
as_daemon = 0;
break;
case 'v':
g_verbose++;
break;
case 'h':
default:
fprintf(stderr, "usage: %s [-v][-D] [-f bindlist_file] [-p port] [-t tunnel_path]\r\n", argv[0]);
return 1;
}
}
chdir(BBSHOME);
attach_SHM();
reload_data();
event_init();
signal_set(&ev_sighup, SIGHUP, sighup_cb, &ev_sighup);
signal_add(&ev_sighup, NULL);
// bind ports
if (port && bind_port(port) < 0)
{
fprintf(stderr, "cannot bind to port: %d. abort.\r\n", port);
return 3;
}
if (port)
bound_ports++;
// bind from port list file
if( NULL != (fp = fopen(config_file, "rt")) )
{
char buf [STRLEN];
while (fgets(buf, sizeof(buf), fp))
{
port = atoi(strtok(buf, " #\r\n"));
if (!port)
continue;
if (bind_port(port) < 0)
{
fprintf(stderr, "cannot bind to port: %d. abort.\r\n", port);
return 3;
}
bound_ports++;
}
fclose(fp);
}
if (!bound_ports)
{
fprintf(stderr, "error: no ports to bind. abort.\r\n");
return 4;
}
/* Give up root privileges: no way back from here */
setgid(BBSGID);
setuid(BBSUID);
if (as_daemon)
{
fprintf(stderr, "start daemonize\r\n");
daemonize(BBSHOME "/run/logind.pid", NULL);
}
// create tunnel
if ( (tfd = tobindex(tunnel_path, 1, _set_bind_opt, 1)) < 0)
{
fprintf(stderr, "cannot create tunnel: %s. abort.\r\n", tunnel_path);
return 2;
}
event_set(&ev_tunnel, tfd, EV_READ | EV_PERSIST, tunnel_cb, &ev_tunnel);
event_add(&ev_tunnel, NULL);
fprintf(stderr, "start event dispatch.\r\n");
event_dispatch();
return 0;
}
// vim:et
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